As internal combustion engines wear, the annular spaces between the pistons and the cylinder tend to increase. In the combustion chamber of each cylinder, an air-fuel mixture is ignited. The expanding gas mixture forces the piston upwards generating power from the engine. In the expansion process, part of the gas mixture is forced between the annular spaces between the piston and the cylinder into the crankcase. These xe2x80x9cblow-byxe2x80x9d gases, which also include oil mist and unburned fuel, accumulate in the crankcase and must be vented from the crankcase to the atmosphere to prevent a potentially dangerous pressure build-up in the crankcase. In addition, unburned fuel can be present in the combustion chambers after the internal combustion engine is shut down. These hydrocarbons cannot get to the crankcase without the pistons moving, but they may escape through open valves and migrate back through the air intake system. In addition, the activated carbon canister may release significant amounts of stored hydrocarbons when a vehicle has not run for a number of days.
Pollution control laws and regulations restrict the emissions from internal combustion engines. As exhaust gases from internal combustion engines have become cleaner, the blow-by gases and evaporative emissions have become a more significant fraction of the total pollution generated from internal combustion engines. In many localities, the pollution control laws and regulations are such that vapors from the internal combustion engines must be cleaned prior to discharge into the atmosphere. The current evaporative emissions requirements require emissions of less than 2.0 grams of fuel vapor over a one-hour test period. It is expected that these requirements will change in the year 2004 to requiring emissions of less than 2.0 grams fuel vapor over a three day test period.
Disclosed herein is an air cleaner assembly, an adsorber member, and a process for reducing pollutants from being discharged into the atmosphere.
The air cleaner assembly comprises a housing comprising a filter element situated therein, an outlet for allowing filtered air to flow to the engine, and an inlet conduit extending from the housing for permitting the entry of air into the housing; a retainer coupled to the inlet conduit, the retainer comprising a wall defining a first open end and a second open end, wherein the wall forms a cuffed portion about the second open end and has an annular recess facing the first open end, wherein a portion of an annular wall of the inlet conduit is seated in the recess; a clamping device disposed about the second open end and the portion of the annular wall to provide an air tight seal between the retainer and housing coupling; and an adsorber member sealingly disposed within the first open end, wherein the adsorber member comprises a silicate adsorbing material free from a zeolite material.
The adsorber member comprises a support comprising a plurality of fluid passageways; and a silicate pollutant treating material free from zeolite disposed onto a surface of the support. In one embodiment, the silicate pollutant treating material comprises sepiolite.
The process for reducing pollutants from being discharged into the atmosphere comprises disposing an adsorber member in a fluid passageway of the air cleaner assembly, wherein the adsorber member comprises a support comprising a plurality of fluid passageways and a silicate pollutant treating material free from zeolite disposed onto a surface of the support; and contacting a fluid flowing through the fluid passageway with the adsorber member.